1980 System A tilt trim. Will trim down, but not up

[kdenfan]

The motor is a 1979 90 HP Mercury, the tilt/trim is the system "A" type. It was working good during our last ski trp until I noticed that the motor wouldn't come up, I could hear the motor working in both directions and checked the fluid everything seemed to be good. Today I finally went out to investigate further. I visually inspected everything just to make sure that there weren't any loose or leaking hoses, there wasn't any. I then loosed the lines at the motor side of the cylinders and fluid did come out. I then decided to remove the whole motor unit (it has the two solenoids mounted on the unit). I took the entire thing apart and did a visual inspection on all of the seals and components. I cleaned the unit, put it back together, put it in the boat and filled it, then attempted to bleed the system per my Seloc manual. Once again it goes down, but not up. Can anyone give me any suggestions as to where to go from here. I am tempted to rebuild each cylinder at this point, but I don't want to unless I need to. Any help would be greatly appreciated. Thanks in advance.

 

[Chris1956]

Re: 1980 System A tilt trim. Will trim down, but not up

So the PTT motor runs in the up direction, and the engine won't tilt? Is the manual tilt valve closed (all the way CCW)?

I would be surprized if it is the cylinders. More likely it is the control valve.

 

[kdenfan]

Re: 1980 System A tilt trim. Will trim down, but not up

Thanks for getting back to me so soon. Yes the manual tilt is closed all the way (all the way CCW). Is there any way to test the control valve? If I disconnect the cylinders on the engine side and then run the tilt up (without a load on them) would that isolate the problem? Can I rebuild that control valve or just buy a new one.

 

[Chris1956]

Re: 1980 System A tilt trim. Will trim down, but not up

I do not think the control valve is rebuildable. I am trying to think of some tests for the control valve. Remember it has to hold the motor down against reverse thrust, but allow the motor to kick up if you hit something.

I think you should remove the hoses on the up side and run the pump and see if the control valve keeps the oil from circulating. If no oil emerges, remove the control valve and run the pump again to isolate the trouble to the control valve. I would not consider the motor to be a load on the PTT system, unless the tilt is binding. You might check for that.

 

[kdenfan]

Re: 1980 System A tilt trim. Will trim down, but not up

I'm going to try that this week. The hoses for "up", are they the smaller hose or the larger ones, because both hoses end at the engine side of the cylinder. As you can see in the first picture (if it loads correctly). I had loosened both hoses one at a time at each cylinder and both had fluid coming out of them when I ran the pump. I thought maybe the pump wasn't working to the cylinders and I was trying to isolate the cylinders themselves. I figured if fluid was getting there it must be the cylinders, but if the pump doesn't produce enough pressure it still might not work. So which one would be the up hoses? Thanks again.

 

[kdenfan]

Re: 1980 System A tilt trim. Will trim down, but not up

One other note. In removing the hoses I noticed that on the starboard side the larger hose was on the outside, while on the port side they were reversed. I was hoping to figure out which hose controlled the up position and it seemed like the larger one did. I'm not positive though.

 

[Chris1956]

Re: 1980 System A tilt trim. Will trim down, but not up

I never figured out which hose did what. Remove both PTT bracket bolts and try to lift the motor. Just to make sure it is not binding. The cylinders are the same on each side. so the change in position of the hoses is normal.

 

[BatDaddy1887]

Re: 1980 System A tilt trim. Will trim down, but not up

When mine had that problem, it was a faulty switch in the control handle. The replacement was only a few bucks. There is a way to test it at the engine where you apply power from the red wire to each of the terminals (green for down as grass is down and blue for up as sky is blue), but I forget the proper procedure to do that. The module at the engine can also be faulty.

 

[kdenfan]

Re: 1980 System A tilt trim. Will trim down, but not up

Ok, so today I removed the cylinders off of the engine side, I pressed the up button and nothing happened, nothing. It didn't engage the motor at all, I tried the trailer button and it worked, but it did not raise (retract) the cylinders so I jumped the solenoid to engage the motor, the solenoid worked (which means that now I have a bad switch as well) but the cylinder did not retract. I turned the bypass knob on the bottom of the motor and reset everything. I pushed the down button and the cylinders moved out. I have now isolated which solenoid does what and marked them accordingly, I have also learned that the smaller lines run the up or retract the cylinders. I then removed the bleeder screw from the "up" side of the cylinders and ran the pump, a small 1/8 stream of fluid came out consistently but not as strong as I thought would. I am still at a loss. The cylinders are getting fluid (not a lot) but I'm not sure what would be an adequate amount to run the cylinders. It almost seems as if there is a block in the lines, but both sides run the same amount out. Just to clarify, I only opened one "up" bleeder screw at a time. Now what? I am starting to suspect that the Chris 1956 is right about the control valve being faulty. I will price one and as soon as I can, order it and hope it fixes the problem, I will also have to order the up switch as well now. The other thing that happened around the same time was the speedometer cable stopped working and stuck at a certain speed on the dial. I don't think these things are related, but I just wanted to throw that out as well. Some forums suggest checking something under the engine compartment but I think that those are the solenoids that I have attached to the tilt motor itself. I also lifted the engine to check for binding and it worked smoothly and flawlessly. Thanks again.

 

[kdenfan]

Re: 1980 System A tilt trim. Will trim down, but not up

Never mind about the switch. when I disconnected the cylinders, I forgot about the trim limiter switch, it works now, but still no up.

 

[kdenfan]

Re: 1980 System A tilt trim. Will trim down, but not up

I have been looking for a replacement control valve, but it says that the part is obsolete. Does this mean that I will have to buy the whole assembly. If so I am in trouble. I don't think that I can afford a new pump for such an old and cheap boat. Any suggestions? CONTROL VALVE ASSEMBLY
List Price: $380.30
Price: $380.30
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PRODUCT OBSOLETE
45197A 2 Control Valve Assembly

 

[Chris1956]

Re: 1980 System A tilt trim. Will trim down, but not up

They were expensive many years ago. That price doesn't surprise me. I had a couple laying around until Hurricane Sandy got into my garage. You might look for a used on on e-Bay.

 

[kdenfan]

Re: 1980 System A tilt trim. Will trim down, but not up

Thanks.

 

[kdenfan]

Re: 1980 System A tilt trim. Will trim down, but not up

Chris 1956, you were right on the money. I went to EBay and found not only the part I needed but the entire motor assembly and I only paid $118 to my door. I installed it and filled it with oil, it worked great. I bled the system and now it is ready for the water again. Thanks for all of your help. I love this forum.:laugh: